Two, or dual-sided direct thermal printing of documents such as transaction documents and receipts is described in U.S. Pat. Nos. 6,784,906 and 6,759,366. In dual-sided direct thermal printing, the printers are configured to allow concurrent printing on both sides of thermal media moving along a feed path through the printer. In such printers a direct thermal print head is disposed on each side of the media along the feed path. In operation each thermal print head faces an opposing platen across the media from the respective print head.
In direct thermal printing, a print head selectively applies heat to paper or other sheet media comprising a substrate with a thermally sensitive coating. The coating changes color when heat is applied, by which “printing” is provided on the coated substrate. For dual-sided direct thermal printing, the sheet media substrate may be coated on both sides.